We keep hearing about how "leaders" are doing everything within their power to make the Church relevant. A Wall Street Journal article by Brett McCracken lists some of the ways -

Quoting Stephen Colbert or referencing Lady GaGa, screening movies like "No Country For Old Men," giving the Pastor a metro-sexual makeover (skinny jeans and an $80 haircut), or using eco-friendly paper for printed materials, and meeting in bars or nightclubs - Some create websites like yourgreatsexlife.com, or writing books like Sex God (by Rob Bell), or delivering sermons with titles like "Biblical Oral Sex" (Mark Driscoll - Seattle's Mars Hill Church)

The reason behind such activity is to stem the tide of young people leaving the Church - some 70% (between the ages of 18 and 22) according to Lifeway Research. And, the reality is, older adults (23 and up) are missing, or irregular, or inattentive, or careless about their Spirituality, as well.

Here's my take on the subject. The attempt to "make the Church relevant" is a practice that comes out of failure to understand the nature of what the Church is - and is about. The Church is the Body of Christ. Christ is relevant - without our help, without our marketing, without our creativity, without our attempt to make Him "culturally acceptable." Those who are His have a clearly defined purpose, mission, empowerment, and goal. It logically follows then that the problem is not the "Church" but the people who are attempting to "be the Church" without an understanding of, or an appreciation for, God's design. When God's people begin to live in the experiences of a Spirit-filled (read: controlled) lifestyle, adopting the Truth of God's Word as the primary priority of their daily life and action, the "Church" will be the most relevant organism on Earth.

My preacher's haircut (if looking "hip" increases the price exponentially) was obviously free. I am not sure he knows enough about "cultural relevance" to preach a sermon on "Creative Christian Sex." But he will arrive Sunday morning with a Word from God. I think that is the only thing that is relevant.

As you say, Christ is relevant, and those know the relevance, follow. Those who do not follow have rejected the relevance. They can try to blame the witness of others, but it is an excuse. His Relevance is apparent to all, just as He declares. Not that we are not to live as the bible dictates, and yes they can point fingers at us each and every day.
Most "Churches" are missing relevant preaching and there is little discipleship given or wanted.
The world follows after people who live terrible lives and have terrible outcomes and yet they never run out of followers. Then people are leaving or not entering the church because some (many?)in the Church live terrible lives with terrible outcomes and it is somehow the churches fault. I go back to the statement that those that are called, follow. Those that are not called leave. Or maybe a lot of the declining "churches" are not part of Christ's Church and cannot have relevancy.